Function control apparatus and program

ABSTRACT

An electronic device includes processing circuitry configured to produce an audio sound from a virtual sound source position. The circuitry also acquires from a user-input a sound position information of a perceived sound source position, and then controls an enable or disable of a function of the electronic device based on a relationship between the virtual sound source position and the perceived sound source position.

TECHNICAL FIELD

The present disclosure relates to a function control apparatus and aprogram.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2012-268048 filed in theJapan Patent Office on Dec. 7, 2012, the entire content of which ishereby incorporated by reference.

BACKGROUND ART

In recent years, electronic devices such as PCs (Personal Computers) andportable phones (smartphones) have become deeply involved in people'slives. Such electronic devices provide various functions to users. Suchfunctions include functions not necessarily desired to be accessed by anunspecified number of users. In order to protect such functions, lockingan electronic device itself or some functions thereof is generallyperformed. For example, technology for simply performing such locking isdescribed in Patent Literature 1.

A general manipulation for locking/unlocking is an input of a password,as also described in Patent Literature 1 described above. However, thepassword may be leaked by being observed surreptitiously as pointed outin Patent Literature 1 and a security level may not be said to be high.Therefore, in Patent Literature 1, a technology for using a combinationof a pressing position on a touch panel and a pressing force in eachposition as an input has been proposed.

CITATION LIST Patent Literature

[PTL 1]

Japanese Patent Laid-Open Publication No. 2011-48665

SUMMARY Technical Problem

However, even in the technology described in Patent Literature 1, sincean appearance of input may be viewed from the outside, an inputmanipulation may be imitated and accordingly a security level may not besaid to be sufficiently high. Further, even when the password is used oreven when the pressing position and the pressing force are used, it isnecessary for a user to memorize a previously set input pattern in orderto perform unlocking. When the user forgets the input pattern, afunction may not be used and there is still room for improvement interms of usability.

Therefore, in the present disclosure, a function control apparatus and aprogram, which are new and improved, and in which usability is improvedwhile securing a security level of a locking for functions of anelectronic device, are proposed.

Solution to Problem

An electronic device includes processing circuitry configured to producean audio sound from a virtual sound source position. The circuitry alsoacquires from a user-input a sound position information of a perceivedsound source position, and then controls an enable or disable of afunction of the electronic device based on a relationship between thevirtual sound source position and the perceived sound source position.

An information processing method includes producing with a speaker anaudio sound from a virtual sound source position and acquiring from auser-input interface a sound position information of a perceived soundsource position. Processing circuitry controls an enable or disable of afunction of the electronic device based on a relationship between thevirtual sound source position and the perceived sound source position.

A non-transitory computer readable storage medium having stored thereincomputer readable instructions that when executed by processingcircuitry cause the processing circuitry to execute an informationprocessing method, the method including producing with a speaker anaudio sound from a virtual sound source position and acquiring from auser-input interface a sound position information of a perceived soundsource position. Processing circuitry controls an enable or disable of afunction of the electronic device based on a relationship between thevirtual sound source position and the perceived sound source position.

Advantageous Effects of Invention

As described above, according to embodiments of the present disclosure,it is possible to improve usability while securing a security level oflocking for functions of an electronic device.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a sound source in a three-dimensionalacoustic space.

FIG. 2 is a diagram illustrating a head-related transfer function in thethree-dimensional acoustic space.

FIG. 3 is a diagram illustrating reproduction of a virtual sound source.

FIG. 4 is a diagram illustrating an example of an apparatusconfiguration for reproducing a virtual sound source.

FIG. 5 is a diagram conceptually illustrating an example of userrecognition using the head-related transfer function.

FIG. 6 is a diagram conceptually illustrating another example of theuser recognition using the head-related transfer function.

FIG. 7 is a diagram illustrating a schematic configuration of a systemaccording to a first embodiment of the present disclosure.

FIG. 8 is a diagram illustrating a mounting state of an HMD according tothe first embodiment of the present disclosure.

FIG. 9 is a perspective view of the HMD when viewed from below accordingto the first embodiment of the present disclosure.

FIG. 10 is a block diagram illustrating a schematic functionalconfiguration of a function control apparatus according to the firstembodiment of the present disclosure.

FIG. 11 is a diagram illustrating an example of a position of a virtualsound source in the first embodiment of the present disclosure.

FIG. 12 is a diagram illustrating an arrangement in a horizontaldirection of positions of the virtual sound source in the firstembodiment of the present disclosure.

FIG. 13 is a diagram illustrating an arrangement in a vertical directionof the positions of the virtual sound source in the first embodiment ofthe present disclosure.

FIG. 14 is a flowchart illustrating an example of a lock control processin the first embodiment of the present disclosure.

FIG. 15 is a flowchart illustrating a variant of the process shown inFIG. 14.

FIG. 16 is a block diagram illustrating a schematic functionalconfiguration of a function control apparatus according to a variant ofthe first embodiment of the present disclosure.

FIG. 17 is a block diagram illustrating a schematic functionalconfiguration of a function control apparatus according to a secondembodiment of the present disclosure.

FIG. 18 is a diagram illustrating an example of a locus of a virtualsound source in the second embodiment of the present disclosure.

FIG. 19 is a flowchart illustrating an example of an unlocking processin the second embodiment the present disclosure.

FIG. 20 is a flowchart illustrating a variant of the process shown inFIG. 19.

FIG. 21 is a block diagram illustrating a schematic configuration of afunction control apparatus according to a third embodiment of thepresent disclosure.

FIG. 22 is a flowchart illustrating an example of an unlocking processin the third embodiment of the present disclosure.

FIG. 23 is a block diagram illustrating a schematic configuration of afunction control apparatus according to a fourth embodiment of thepresent disclosure.

FIG. 24 is a flowchart illustrating an example of an unlocking processin the fourth embodiment of the present disclosure.

FIG. 25 is a block diagram illustrating a hardware configuration of aninformation processing apparatus.

DESCRIPTION OF EMBODIMENTS

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to accompanying drawings. Further, inthe present specification and drawings, components having substantiallythe same functional configuration are denoted by the same referencenumerals and a repeated description is omitted.

Further, a description will be given in the following order.

-   1. Basic Idea of User Recognition Using Head-Related Transfer    Function-   2. Embodiments of the Present Disclosure-   2-1. First Embodiment-   2-2. Second Embodiment-   2-3. Third Embodiment-   2-4. Fourth Embodiment-   3. Hardware Configuration-   4. Supplemental Remarks

(1. Basic Idea of User Recognition Using Head-related Transfer Function)

In embodiments of the present disclosure which will be described below,a user is recognized using a head-related transfer function. First, abasic idea of the user recognition using this head-related transferfunction will be described with reference to FIGS. 1 to 6.

(Head-Related Transfer Function)

FIG. 1 is a diagram illustrating a sound source in a three-dimensionalacoustic space.

A three-dimensional acoustic space R is a space around a user U who is alistener, and has a sound source S present therein. In the followingdescription, a position of the sound source S is expressed using amoving radius r and deflection angles theta and phi in a polarcoordinate system in which a position of the user U is an origin. Theposition of the user U may be exactly at a middle point of a lineconnecting right and left ears of the user U. The moving radius r is adistance from this point to the position of the sound source S. Further,the deflection angle theta is an angle formed between a direction of afront of the user U and a direction of the sound source S within ahorizontal plane. The deflection angle phi is an angle formed between ahorizontal plane including the position of the user U and the directionof the sound source S within a vertical plane.

FIG. 2 is a diagram illustrating a head-related transfer function in athree-dimensional acoustic space.

Here, in a sound wave arriving at an eardrum of a user U (hereinafterreferred to as a heard sound), a specific frequency component of thesound wave radiated from a sound source S (hereinafter referred to as anoriginal sound) is emphasized or attenuated due to reflection anddiffraction at the head or the ear of the user U. Since a process inwhich the original sound is reflected or diffracted may also differbetween a left ear and a right ear of the user U, frequency componentsof the heard sound differ. Further, since a distance from the soundsource S differs between the left ear and the right ear of the user U,phases of the heard sound may also differ.

In this case, a transfer function expressing a change from the originalsound to the heard sound is a head-related transfer function (HRTF). TheHRTF greatly depends on, particularly, a shape of a head, a shape of anauricle, a shape of an external auditory canal, sound impedance of skinand the like of the user. In other words, the HRTF is a function varyingdepending on each user. Further, the HRTF varies depending on a positionof the sound source S in the three-dimensional acoustic space R.

In FIG. 2, the sound wave from the sound source S changes in ahead-related transfer function HRTF_L and arrives at the eardrum of theleft ear of the user U, and changes in a head-related transfer functionHRTF_R and arrives at the eardrum of the right ear of the user U. Asdescribed above, the HRTF is specific to each user and varies dependingon the position of the sound source S. Therefore, the HRTF_L and theHRTF_R are functions that depend on the user U and the moving radius rand the deflection angles theta and phi indicating the position of thesound source S and are expressed as HRTF_L(U, r, theta, phi) andHRTF_R(U, r, theta, phi).

A brain that is a sense center of the user U recognizes a relationshipbetween the position (r, theta, phi) of the sound source S and thehead-related transfer function HRTF through experience. Accordingly, theuser U can recognize the position (r, theta, phi) of the sound source Sbased on the heard sound changed in HRTF_L(U, r, theta, phi) andHRTF_R(U, r, theta, phi).

The HRTF is a transfer property between the original sound and the heardsound expressed in a frequency domain. When this HRTF is subjected to aninverse discrete Fourier transform, a head-related impulse response(HRIR) may be obtained. The HRIR is the transfer property between theoriginal sound and the heard sound expressed in a time domain, and isincluded in the head-related transfer function in a broad sense. TheHRIR also differs between the left ear and the right ear, is a functionthat depends on the user U and the moving radius r and the deflectionangles theta and phi indicating the position of the sound source S, andis expressed as HRIR_L(U, r, theta, phi) and HRIR_R(U, r, theta, phi),similar to the HRTF.

FIG. 3 is a diagram illustrating reproduction of a virtual sound source.

A three-dimensional acoustic space V is a virtual space recognized as aspace around a user U who is a listener. When measured head-relatedimpulse responses HRIR_L(U, r, theta, phi) and HRIR_R(U, r, theta, phi)are subjected to convolution with original sound X, the original sound Xchanges similarly to a heard sound radiated from a sound source Spresent in a position (r, theta, phi) in a real three-dimensionalacoustic space R and arriving at an eardrum of the user U. Therefore,when a sound wave after the convolution is radiated from the vicinity ofthe eardrum of the user U, the user perceives a sound source located inthe position (r, theta, phi) in the virtual three-dimensional acousticspace V. This may be called a kind of acoustic illusion. In this case,an output signal Y_(L) to a left ear of the user and an output signalY_(R) to a right ear are represented by the following mathematicalequations 1 and 2, respectively. Further, “*” indicates a convolutionoperation.Y _(L) =X*HRIR_L(U, r, θ, φ)   (Equation 1)Y _(R) =X*HRIR_R(U, r, θ, φ)   (Equation 2).

The HRIR of the user U is obtained by reproducing an impulse signal, aTSP (Time Stretched Pulse) signal or the like as a sound source S in thereal sound space R, measuring HRTF_L and HRTF_R in ,a frequency domainby receiving a heard sound using microphones mounted on a left ear and aright ear of the user U, and performing an inverse discrete Fouriertransform on HRTF_L and HRTF_R. Further, the HRIR may be obtaineddirectly in a time domain from the measured impulse reply signal.

Since the HRIR depends on the moving radius r and the deflection anglestheta and phi indicating the position of the sound source S as describedabove, it is desirable for the HRIR to be measured in each position inwhich the sound source S is likely to be located. For example, measuringthe HRIR in all combinations of the deflection angles theta and phiwhile fixing the moving radius r up to the sound source S to apredetermined distance such as 1 m and changing the deflection angletheta or the deflection angle phi by 1 degree may be considered.Although minimum resolution of an azimuth angle recognized by hearingdepends on a direction as well, since it is about 1 degree, the virtualsound source present in an arbitrary position in which the distance fromthe user U in the three-dimensional acoustic space V is r can bereproduced by measuring the HRIR at an observation point on a mesh inwhich the deflection angles theta and phi are changed by 1 degree.

Further, for example, a headphone (including an inner ear typeheadphone) or the like is used for the radiation of the sound wave fromthe vicinity of the eardrum of the user U. In this case, the position ofthe sound source can be caused to he perceived by the user U moreexactly by applying correction of a transfer property of an externalauditory canal, correction of an acoustic feature of a speaker driver ofthe headphone, and the like considering a mounting position of theheadphone. Further, a transaural system, which will be described below,may be used for the radiation of the sound wave to the vicinity of theeardrum of the user U.

FIG. 4 is a diagram illustrating an example of an apparatusconfiguration for reproducing a virtual sound source.

In an apparatus 10, convolution of input original sound data (monaural)and HRIR_L or HRIR_R is executed by left and right FIR (Finite ImpulseResponse) filters 11L and 11R. The original sound data is input, forexample, as a digital signal with a sampling frequency of 44.1 KHz and aquantization bit number of 16 bits. Here, when a tap length of an HRIRcoefficient is assumed to be 512 samples, the convolution in the FIRfilters 11L and 11R is a product-sum operation process of 512 taps. TheFIR filters may be mounted as operational hardware such as a DSP(Digital Signal Processor) or may be mounted as software signalprocessing of a CPU (Central Processing Unit).

As a result of the convolution in the FIR filters 11L and 11R, an outputsignal Y_(L) to the left ear and an output signal Y_(R) to the right earof the user may be obtained. These signals are converted from a digitalsignal to an analog signal by D/A converters 12L and 12R, amplified byamplifiers 13L and 13R, and output from speakers 14L and 14R to a user Uwho is a listener. The speakers 14L and 14R are headphones or speakershaving a function of outputting separate sounds to the left ear and theright ear of the user U, such as speakers constituting a transauralsystem, as will be described below.

Here, the FIR filters 11L and 11R are controlled by a CPU 15. The CPU 15acquires an HRIR coefficient from an HRIR coefficient table 16 stored ina storage device or the like, according to an input sound sourceposition. The HRIR coefficient is, for example, tied to a user ID thatidentifies the user U and stored for each of HRIR_L and HRIR_R for eachcombination of the moving radius r and the deflection angles theta andphi indicating the position of the sound source S.

(User Recognition Using Head-Related Transfer Function)

The HRTF and HRIR, which are head-related transfer functions, arefunctions specific to respective users, as described above. The user Uempirically learns how an original sound radiated from the sound sourceS present in the position (r, theta, phi) by his or her HRTF becomes theheard sound. The user U is able to recognize the position of the soundsource S from the heard sound through such learning.

Therefore, the user does not perceive the sound source located in theposition (r, theta, phi) in the virtual three-dimensional acoustic spaceV, for example, even when sound obtained by performing convolution ofhead-related impulse responses HRIR_L(U′, r, theta, phi) and HRIR_R(U′,r, theta, phi) of the other user U′ with the original sound X isradiated from the vicinity of an eardrum of the user U in thereproduction of the sound source in the virtual three-dimensionalacoustic space V shown in FIG. 3. This is because a change of theoriginal sound X by the HRTF of the other user U′ differs from a changeby the HRTF of the user U that the user U is empirically learning. Thus,it is a generally well-known phenomenon that an individual difference inperception of the localization of the virtual sound source isremarkable.

When the original sound X with which the HRIR calculated from the HRTFthat is not the HRTF of the user is subjected to convolution ispresented to the user U, the position of the sound source is notcorrectly perceived as described above. Particularly, it is verydifficult to perform exact localization in any front or verticalposition (front localization and vertical localization). In this case,the sound source is known to be localized inside the head of the user U(in-head localization) or in an incorrect position behind the user U(backward localization) and perceived.

On the other hand, when the original sound X with which the head-relatedimpulse responses HRIR_L(U, r, theta, phi) and HRIR_R(U, r, theta, phi)of the user U are subjected to convolution is presented, only the user Ucan correctly perceive that the sound source is present in the position(r, theta, phi).

A basic idea of the user recognition using the head-related transferfunction is based on discovery described above. In other words, the userrecognition using the head-related transfer function is to recognize theuser U by using the head-related transfer function such as the HRIR ofthe user U as a template and estimating a position of a sound sourcevirtually generated using the head-related transfer function. In thisrecognition, the user U is recognized as himself or herself, forexample, only when the position of the virtually generated sound sourceis exactly estimated within a predetermined minute error range.

Further, the user recognition using the head-related transfer functionmay be used not only to recognize the user himself or herself asdescribed above, but also to recognize an attribute of the user. Sincethe HRTF is a function determined, for example, depending on a shape ofa head, a shape of an auricle, a shape of an external auditory canal,sound impedance of skin and the like of the user as described above, theHRTF may also be considered to be similar to some extent between usershaving such similar attributes. Accordingly, a level of the recognitionmay be adjusted from strict recognition limited to the user himself orherself to relatively lax recognition capable of recognizing a usergroup having a predetermined attribute by regulating an error rangeallowed in the recognition. Therefore, “recognition of the user U” inthe following description may be replaced with “recognition of whetheror not a user is a user having a predetermined attribute.”

FIG. 5 is a diagram conceptually illustrating an example of userrecognition using a head-related transfer function.

For example, a sound source S_(T) present in a position (r, theta₁, 0)in front of a user U is virtually reproduced by performing convolutionof head-related impulse responses HRIR_L(U, r, theta₁, 0) and HRIR_R(U,r, theta₁, 0) with original sound X and presented to a listener. In thiscase, if the listener is the user U, the listener may correctly perceivethe position of the sound source S_(T). On the other hand, if thelistener is not the user U, the listener is not able to correctlyperceive the position of the sound source S_(T) and erroneouslyperceives the position, for example, to be a sound source S_(F) locatedbehind the listener. Therefore, if the position of the sound sourceS_(T) present in front of the user U is estimated, the user U can berecognized with high precision.

FIG. 6 is a diagram conceptually illustrating another example of userrecognition using a head-related transfer function.

When the original sound X with which the HRIR calculated from the HRTFthat is not the HRTF of the user U is subjected to convolution ispresented to the user U as described above, the sound source islocalized in an incorrect position inside the head of the user U orbehind the user U and perceived. A range in which this incorrectposition is distributed is particularly narrow in a vertical directionof the user U. In other words, when the original sound X with which theHRIR calculated from the HRTF that is not the HRTF of the user U issubjected to convolution is presented, it is very difficult for alistener to identify a height of the sound source.

For example, a sound source S_(T) present in a position (r, 0, phi₁) infront of the user U is virtually reproduced by performing convolution ofhead-related impulse responses HRIR_L(U, r, 0, phi₁) and HRIR_R(U, r, 0,phi₁) with original sound X and presented to the listener. In this case,if the listener is the user U, the listener is able to correctlyperceive the position of the sound source S_(T). On the other hand, ifthe listener is not the user U, the listener is not able to correctlyperceive the position of the sound source S_(T) and erroneouslyperceives the position to be a sound source S_(F) located at the sameheight as the listener behind the listener in many cases. Therefore, ifthe position of the sound source S_(T) present in any one of a pluralityof positions at different heights when viewed from the user U isestimated, the user U can be recognized with high precision.

(2. Embodiments of Present Disclosure)

Next, some embodiments in which a lock state of an electronic device iscontrolled using the basic idea described above will be described.

(2-1. First Embodiment)

First, a first embodiment of the present disclosure will be describedwith reference to FIGS. 7 to 16. In the present embodiment, a virtualsound source reproduced using the head-related transfer function isoutput from a headphone of a head mount display (HMD). A user hearingthe output sound source replies with an estimated position of the soundsource, for example, using an input button or the like of the HMD. Whenthe reply is correct, a function of the HMD, a converter or a playbackdevice providing content to the HMD is unlocked.

Here, the head-related transfer function used for reproduction of thevirtual sound source may be, for example, a head-related transferfunction of a specific user measured in advance. Further, thehead-related transfer function may be, for example, an averagehead-related transfer function of a user group having a predeterminedattribute. As described above, the head-related transfer function isspecific to each user, but when there is a difference in sizes of aheads of users and a state of skin according to an attribute like anadult and a child, it is considered that there may be a difference inthe average head-related transfer function for each attribute.Accordingly, it can be determined whether the user has the attribute,for example, whether the user is an adult or not, through thereproduction of the sound source using the average head-related transferfunction.

(System Configuration)

FIG. 7 is a diagram illustrating a schematic configuration of a systemaccording to a first embodiment of the present disclosure. Referring toFIG. 7, the system 40 includes an HMD 20 and a converter 30. The HMD 20is a device mounted on a head of a user for displaying an image for eachof left and right eyes of the user and outputting sound to each of leftand right ears of the user. The converter 30, for example, converts dataof an image and sound (e.g., constructed for reproduction in a normaldisplay) output from a playback device, such as a recorder, a gameconsole, or a television tuner, to data of an image and sound that canbe output on the HMD 20, and provides the converted data to the HMD 20.

In an illustrated example, the HMD 20 and the converter 30 are connectedby a cable. However, in other embodiments of the present disclosure, theHMD 20 and converter 30 may be wirelessly connected or the HMD 20 andconverter 30 may be integrally formed. Alternatively, when the HMD 20reproduces an image and sound constructed for reproduction in the HMD inadvance, the converter 30 is unnecessary, and the data of the image andthe sound output from the playback device such as a recorder, a gameconsole or a television tuner may be directly input to the HMD 20.

Further, since well-known technology as described, for example, inJapanese Patent Laid-Open Publication No. 2008-83290 may be used as theconfiguration for reproduction of the image and the sound using the HMD20, a detailed description is omitted herein.

FIG. 8 is a diagram illustrating a mounting state of the HMD accordingto the first embodiment of the present disclosure. Referring to FIG. 8,the HMD 20 is mounted on the head of the user U to cover right and lefteyes of the user. Further, an inner ear type headphone 21 connected tothe HMD 20 is mounted in right and left ears of the user U.

Further, in an illustrated example, the HMD 20 is a non-see throughtype, but the HMD may be a see-through type in other embodiments of thepresent disclosure. In that case, the HMD may have a glasses shape asdescribed, for example, in Japanese Patent Laid-Open Publication No.2008-83290. Further, the headphone 21 may not necessarily be connectedto the HMD 20 and may be connected, for example, to the converter 30separately from the HMD.

FIG. 9 is a perspective view when the HMD according to the firstembodiment of the present disclosure is viewed from below. Referring toFIG. 9, the HMD 20 includes a display unit 22 and a manipulation unit23, in addition to a headphone 21. The headphone 21 includes a headphone21L mounted on a left ear of the user U and a headphone 21R mounted on aright ear of the user U. Further, the display unit 22 includes a displayunit 22L that displays an image toward a left eye of the user, and adisplay unit 22R that displays an image toward a right eye of the user.Sound is independently output to the right ear and the left ear of theuser, and the image is independently displayed to the right eye and theleft eye of the user by the headphone 21 and the display unit 22. Forexample, an LCD (Liquid Crystal Display) or an organic EL(Electroluminescence) display may be used for the display unit 22.

The manipulation unit 23 includes buttons provided on a lower surface ofthe HMD 20. In the illustrated example, the manipulation unit 23includes a power button 23 a, a direction/menu button 23 b and a volumebutton 23 c. Further, in other embodiments of the present disclosure,the manipulation unit 23 may include types of buttons different fromthose in the illustrated example, or switches or levers rather than thebuttons. Since the view of the user is occupied by an image (includingan image of an external world viewed through transmission when the HMDis a see-through type) displayed on the display unit 22 while the useris wearing the HMD 20, the user manipulates the manipulation unit 23blind, i.e., without viewing the manipulation unit 23.

The HMD 20 as described above exhibits excellent performance compared toa normal display, for example, in terms of beauty of an image, a senseof reality felt by the user, or immersion. On the other hand, since adistance between the display unit and the eyes of the user is short,health of growing children may be affected. Therefore, for example, itis recommended that a so-called child lock be set to prevent a childfrom using the HMD 20.

The child lock is a mechanism in which input of a password is requested,for example, when it is determined that the HMD 20 has been mounted inorder to prevent a child from using the HMD 20, and a lock set for afunction of the HMD 20 is released to allow the HMD 20 to be used onlywhen a correct password is input. However, since the user manipulatesthe manipulation unit 23 of the HMD 20 blind as described above,although there is no problem with simple manipulations such asreproduction control or volume adjustment for content, complexmanipulations such as the input of the password are not easy.

Further, as described above, it may not be said that a security level ofa setting of the lock by the input of the password is high. For example,a password set by a parent may be easily guessed by a child with whomthey live. When a complex password that is hard for the child to guessis set, inputting the password using the manipulation unit 23 asdescribed above is troublesome and the parent is likely to forget thepassword and not be able to use the HMD 20.

Therefore, in the present embodiment, a function control apparatus aswill be described below is provided to improve usability while securinga security level of locking for the function.

(Configuration of Function Control Apparatus)

FIG. 10 is a block diagram illustrating a schematic functionalconfiguration of a function control apparatus according to the firstembodiment of the present disclosure. Referring to FIG. 10, the functioncontrol apparatus 100 includes a mounting detection unit 101, ahead-related transfer function acquisition unit 103, a virtual soundsource position setting unit 107, a generation unit 109, a decodingcircuit 113, a reproduction unit 115, a reply acquisition unit 117, adetermination unit 119 and a locking unit 121. Further, the functioncontrol apparatus 100 refers to head-related transfer function data 105and original sound data 111 stored in a storage device or the like.

The function control apparatus 100 is included in the system 40 andcontrols the lock of the function of the HMD 20. For example, thefunction control apparatus 100 may be incorporated in the HMD 20.Further, the function control apparatus 100 may be incorporated in theconverter 30. Alternatively, the function control apparatus 100 may beincluded in the system 40 as an independent apparatus. When the functioncontrol apparatus 100 is not incorporated in the HMD 20, detection ofmounting by the mounting detection unit 101, reproduction of sound databy the reproduction unit 115, acquisition of a reply by the replyacquisition unit 117 and control of function locking by the locking unit121 may be executed through wired or wireless communication with the HMD20. The function control apparatus 100 may be realized, for example, bya hardware configuration of an information processing apparatus thatwill be described below.

The mounting detection unit 101 detects that the HMD 20 has been mountedby the user, for example, based on a detection value of a sensor (acontact sensor, a gyro sensor, an acceleration sensor or the like)provided in the HMD 20. Alternatively, the mounting detection unit 101may detect that the HMD 20 has been mounted by the user when amechanical switch provided in the HMD 20 is switched due to the userwearing the HMD 20 or due to an explicit manipulation of the user. Whenit is detected that the HMD 20 has been mounted by the user, themounting detection unit 101 causes the virtual sound source positionsetting unit 107 to start a process of unlocking the function of the HMD20. Further, the function of the mounting detection unit 101 may bereplaced, for example, with detection of a state change of the HMD 20from a standby state to a start-up state due to the user pushing thepower button 23 a of the manipulation unit 23.

The head-related transfer function acquisition unit 103 acquires ahead-related transfer function prepared in advance with reference to thehead-related transfer function data 105. Here, the acquired head-relatedtransfer function may be a head-related transfer function measured forthe user U of the HMD 20 in advance. Alternatively, the head-relatedtransfer function may be a head-related transfer function provided as anaverage head-related transfer function of a user group having a commonattribute. As described above, the head-related transfer functiondepends on the position (r, theta, phi) of the sound source S, inaddition to the user U (or an attribute of the user U). Therefore, thehead-related transfer function acquisition unit 103 acquires theinformation of the head-related transfer function measured and stored inadvance with reference to the head-related transfer function data 105using the position of the virtual sound source acquired from the virtualsound source position setting unit 107. Here, the acquired head-relatedtransfer function is, for example, an HRIR. The head-related transferfunction acquisition unit 103 provides information of the acquiredhead-related transfer function to the generation unit 109.

The virtual sound source position setting unit 107 randomly sets theposition (r, theta, phi) of the virtual sound source. The virtual soundsource position setting unit 107 sets any position of the virtualthree-dimensional acoustic space V as the position of the virtual soundsource (hereinafter referred to as a first position). In the presentembodiment, since the reply with the position of the virtual soundsource is performed by a selection from nine options as will bedescribed below, the virtual sound source position setting unit 107 setsany one of nine positions in the three-dimensional acoustic space Vcorresponding to the nine options as the position of the virtual soundsource. The virtual sound source position setting unit 107 providesinformation of the set position of the virtual sound source to thehead-related transfer function acquisition unit 103 and thedetermination unit 119.

As described above, the head-related transfer function acquisition unit103 acquires a head-related transfer function from the head-relatedtransfer function data 105 based on the position set by the virtualsound source position setting unit 107. Here, the position set by thevirtual sound source position setting unit 107 is any one of the ninepositions. Therefore, head-related transfer functions of at least thenine positions described above are prepared in the head-related transferfunction data 105 in advance.

The generation unit 109 generates sound data obtained by virtuallyreproducing the sound source present in the first position in thethree-dimensional acoustic space V using the head-related transferfunction. The generation unit 109 acquires the information of thehead-related transfer function in the first position set by the virtualsound source position setting unit 107 from the head-related transferfunction acquisition unit 103. The generation unit 109 may be realizedusing an FIR filter, similar to, for example, a case of the apparatus 10shown in FIG. 4. The generation unit 109 processes the data of theoriginal sound provided from the decoding circuit 113 using thehead-related transfer function and generates the sound data of thevirtual sound source. The generation unit 109 provides the generatedsound data to the reproduction unit 115.

The decoding circuit 113 decodes the original sound data 111. Theoriginal sound data 111 is, for example, monaural sound data that hasbeen MP3-compressed at a sampling frequency of 44.1 KHz and in aquantization bit number of 16 bits. The decoding circuit 113 decodesthis sound data, demodulates the sound data into a PCM signal, andprovides the PCM signal to the generation unit 109.

The reproduction unit 115 reproduces the sound data provided from thegeneration unit 109 toward the user. The reproduction unit 115 may be,for example, an interface connected to the headphone 21 and may includea D/A converter, an amplifier or the like. The reproduction unit 115provides the sound data to the headphone 21 to be output toward theuser. In this case, the headphones 21L and 21R shown in FIG. 9 functionas the speakers 14L and 14R shown in FIG. 4.

The reply acquisition unit 117 acquires the position of the virtualsound source in the three-dimensional acoustic space V estimated by theuser hearing the sound data reproduced by the reproduction unit 115through the headphone 21 (hereinafter referred to as the secondposition) as a reply. The reply acquisition unit 117 is, for example, aninterface connected to the manipulation unit 23, and acquiresinformation indicating a position input by the user using themanipulation unit 23, specifically, the direction/menu button 23 b. Thereply acquisition unit 117 provides the acquired information of thesecond position to the determination unit 119.

The determination unit 119 determines whether the HMD 20 is to beunlocked to validate a function such as content viewing based on arelationship between the first position set by the virtual sound sourceposition setting unit 107 and the second position acquired by the replyacquisition unit 117. For example, when sound data is generated usingthe head-related transfer function of the user U, the determination unit119 may determine that the HMD 20 is to be unlocked if the firstposition and the second position match. This is because a user correctlyperceiving the position of the virtual sound source is estimated to bethe user U himself or herself. Further, for example, when the sound datais generated using an average head-related transfer function of usershaving a common attribute, e.g., users who are “adults,” thedetermination unit 119 may determine that the HMD 20 is to be unlockedif an error between the first position and the second position is withina predetermined range. This is because a user correctly perceiving theposition of the virtual sound source to some extent is estimated to bean “adult” a predetermined age or older. The determination unit 119outputs a result of the determination to the locking unit 121.

The locking unit 121 executes lock control of the HMD 20 based on theresult of the determination in the determination unit 119. For example,when the determination unit 119 determines that the HMD 20 is to beunlocked, the locking unit 121 unlocks the HMD 20 to validate a contentreproduction function of the HMD 20. On the other hand, when thedetermination unit 119 does not determine that the HMD is to beunlocked, the locking unit 121 continuously maintains a lock stateleaving the content reproduction function of the HMD 20 invalid.

Further, among the components described above, components other than thecomponents illustrated as specific members are realized, for example, bya CPU, a RAM (Random Access Memory), a ROM (Read Only Memory) and thelike. The same applies to components that will be described in thefollowing embodiments.

(Example of Position of Virtual Sound Source)

FIG. 11 is a diagram illustrating an example of positions of a virtualsound source in the first embodiment of the present disclosure.Referring to FIG. 11, in the present embodiment, a virtual screen 150 ispresented to an observer. The virtual screen 150 is a virtual screenrecognized by the user for which an image is displayed toward right andleft eyes of the user by the display units 22L and 22R of the HMD 20. Onthe virtual screen 150, a position S₅ is arranged at a center whenviewed by the user, and positions S₁ to S₄ and positions S₆ to S₉ arearranged in top, bottom, left, right, top left, top right, bottom leftand bottom right positions around the position S₅, respectively. Asdescribed above, in the present embodiment, the first position set bythe virtual sound source position setting unit 107 is selected fromamong the nine positions. Further, in response thereto, the secondposition indicated by the reply of the user acquired by the replyacquisition unit 117 may also be selected from among the nine positions.

Thus, the head-related transfer function may be prepared in advance fora position included in at least a predetermined position group byselecting each of the first position and the second position from thepredetermined position group, thereby simplifying the measurement orgeneration of the head-related transfer function. Further, the reply ofthe user estimating the position of the virtual sound source may beacquired by selection from options, thereby simplifying the input andthe determination of the reply. Further, the number of positionsincluded in the position group is not limited to 9 and may be anynumber.

Further, the positions S₁ to S₉ of the virtual sound source may bedisplayed as images on the virtual screen 150, as illustrated. As thepositions S₁ to S₉ are displayed, the user may easily reply, forexample, by inputting any of numbers “1” to “9” attached to thepositions S₁ to S₉, respectively, when hearing the sound data andreplying with the position of the virtual sound source. Further, thenumber may not be attached to the positions S₁ to S₉. In this case, theuser may reply, for example, by inputting a direction corresponding tothe position of the virtual sound source using the direction/menu button23 b of the manipulation unit 23.

Alternatively, the reply of the user may be acquired based on a resultof detecting a line of sight or a gesture of the user. For example, acamera for detecting the line of sight of the user is installed in theHMD 20, and a position closest to a gazing point of the user when thesound data is reproduced may be acquired as a reply of the user.Further, for example, a camera for detecting the gesture of the user maybe installed in a portion corresponding to a forehead of the user of theHMD 20 or in a position in which a user wearing the HMD 20 can becaptured, and the reply of the user may be recognized from the gestureof the user when the sound data is reproduced. In this case, forexample, a corresponding gesture may be set for each of the positions S₁to S₉ in advance (e.g., when the position S₁ is replied, a left arm isstretched out to the side and a tip is turned up from an elbow).Further, since a well-known technology may be used for a configurationfor detecting the line of sight of the user or a configuration fordetecting the gesture of the user, a detailed description is omittedherein.

FIG. 12 is a diagram illustrating an arrangement in a horizontaldirection of the positions of the virtual sound source in the firstembodiment of the present disclosure. In FIG. 12, a horizontalcross-sectional view of the virtual three-dimensional acoustic space Varound the user at a height of a head of the user is schematicallyshown. In the present embodiment, the positions of the virtual soundsource are arranged on a virtual screen 150 at a distance r in a frontof the user. The distance r may be set to be the same as a virtualviewing distance of the HMD 20, namely, a virtual distance from the userU to the virtual screen 150. For example, when the virtual viewingdistance is 20 m, the distance r may be 20 m.

In an illustrated example, a position S₅ of the virtual sound source is(r, 0, 0) in the three-dimensional acoustic space V. Further, a positionS₄ of the virtual sound source is (r, −theta₁, 0) in thethree-dimensional acoustic space V, and a position S₆ of the virtualsound source is (r, theta₁, 0). Accordingly, a distance between eitherthe position S₄ and the position S₅ or the position S₅ and the positionS₆ is r*tan theta₁.

In this case, a distance from a viewpoint of the user to the position S₄and the position S₆ set on the virtual screen 150 is slightly greaterthan r, but for example, when r is about 20 m and theta₁ is about 3degrees to 5 degrees, a difference therebetween is in a range that maybe neglected as an error. When the distance from the viewpoint of theuser to the position S₄ and the position S₆ on the virtual screen 150 isexactly r, the virtual viewing distance of the HMD 20, i.e., the virtualdistance (e.g., 20 m) from the user to the position S₅, is r*costheta₁and the distance between the position S₄ and the position S₅ and thedistance between the position S₅ and the position S₆ may be set tor*sintheta₁.

FIG. 13 is a diagram illustrating an arrangement in a vertical directionof the positions of the virtual sound source in the first embodiment ofthe present disclosure. In FIG. 13, a vertical cross-sectional view ofthe virtual three-dimensional acoustic space V around the user in afront-back direction of the user is shown schematically. As describedabove, in the present embodiment, the positions of the virtual soundsource are arranged on the virtual screen 150 at the distance r in frontof the user, and the distance r may be set to be the same as the virtualviewing distance of the HMD 20.

In an illustrated example, a position Ss of the virtual sound source is(r, 0, 0) in the three-dimensional acoustic space V. Further, a positionS₂ of the virtual sound source is (r, 0, phi₁) in the three-dimensionalacoustic space V, and a position S₈ of the virtual sound source is (r,0, −phi₁). Accordingly, a distance between the position S₂ and theposition S₅ and a distance between the position S₅ and the position S₈is r*tanphi₁. In this case, the distance from the viewpoint of the userto the position S₂ and the position S₈ set on the virtual screen 150 isslightly greater than r, but for example, when r is about 20 m and phi₁is about 3 degrees to 5 degrees, a difference therebetween may beneglected as an error. When the distance from the viewpoint of the userto the position S₂ and the position S₈ on the virtual screen 150 isexactly r, the virtual viewing distance of the HMD 20, i.e., the virtualdistance (e.g., 20 m) from the user to the position S₅ is r*cos theta₁and the distance between the position S₂ and the position S₅ and thedistance between the position S₅ and the position S₈ may be set tor*sintheta₁.

Positions in the three-dimensional acoustic space V of positions S₁, S₃,S₇ and S₉, which are not illustrated, are set similarly to the positionsS₂, S₄ to S₆ and S₈ described above. In other words, the position S₁ is(r, −theta₁, phi₁), the position S₃ is (r, theta₁, phi₁), the positionS₇ is (r, −theta₁, −phi₁), and the position S₉ is (r, theta₁, −Phi₁).

In the above example, a minimum value (minimum resolution) of theta₁ andphi₁ that allow a user to identify a difference between the positions ofthe virtual sound source is about 3 degrees. If the values of theta₁ andphi₁ are too great, the difference between the positions of the soundsource may be identified by people other than the user U, andaccordingly, it is desirable for the values of theta₁ and phi₁ to beabout 3 degrees to about 5 degrees. Further, when the virtual soundsource is reproduced using the average head-related transfer function ofa user group having a common attribute, accuracy of identification ofthe position of the virtual sound source by the user is not very highand it is desirable for each user belonging to the user group to be ableto identify the same position of the virtual sound source, andaccordingly, the values of theta₁ and phi₁ may be set, for example, tovalues greater than 5 degrees.

(Process Flow)

FIG. 14 is a flowchart illustrating an example of a lock control processin the first embodiment of the present disclosure.

As described above, in the present embodiment, in the function controlapparatus 100, an unlocking process starts as the mounting detectionunit 101 detects that the HMD 20 has been mounted by a user (step S101).First, the virtual sound source position setting unit 107 randomly setsthe position of the virtual sound source (step S103). Here, the virtualsound source position setting unit 107 randomly selects the position ofthe virtual sound source from among the above-described positions S₁ toS₉.

Next, the head-related transfer function acquisition unit 103 acquiresan HRIR function in the position of the virtual sound source set in stepS103 from data stored as the head-related transfer function data 105 inadvance (step S105). Here, the acquired HRIR function may be, forexample, an HRIR function measured for a specific user in advance or maybe an HRIR function provided as an average head-related transferfunction of users having a predetermined attribute.

Then, the generation unit 109 generates sound data of the virtual soundsource by performing convolution of the HRIR function acquired in stepS105 with original sound data (step S107). Then, the reproduction unit115 outputs the sound data to the user through the headphone 21 of theHMD 20 (step S109).

Then, the reply acquisition unit 117 acquires a reply indicating theposition of the virtual sound source estimated by the user via themanipulation unit 23 of the HMD 20 (step S111). Here, a predeterminedstandby time may be set in consideration of a time taken for a thoughtand operation of the user between step S109 and step S111.

Then, the determination unit 119 determines whether the positionindicated by the reply acquired in step S111 (a second position) matchesthe position of the virtual sound source set in step S103 (a firstposition) (step S113). Here, when it is not determined that thepositions match, the determination unit 119 determines “unlockingfailure” and the locking unit 121 does not unlock the HMD 20 leaving thefunction invalid (step S115).

On the other hand, when it is determined in step S113 that the positionindicated by the reply matches the position of the virtual sound source,the determination unit 119 further determines whether the reproductionof the virtual sound source in steps S103 to S109 has been repeated apredetermined number of times (step S117). Here, when it is determinedthat the reproduction of the virtual sound source has been repeated apredetermined number of times, the determination unit 119 determines“unlocking success” and the locking unit 121 unlocks the HMD 20 tovalidate the function (step S119).

On the other hand, when it is not determined in step S117 that thereproduction of the virtual sound source has been repeated apredetermined number of times, a process of reproducing the virtualsound source from step S103 is executed again. In this case, theposition of the virtual sound source may be randomly set again in stepS103. Further, the predetermined number of times may be 1 and, in thiscase, step S117 is not executed.

In the illustrated example, the reproduction of the virtual sound sourceand the acquisition of the reply from the user are repeated apredetermined number of times while changing the position of the virtualsound source (although the same positions may be consecutive as a resultof the random selection). Accordingly, for example, it is possible toprevent a situation in which unlocking is accidentally performed when achild whose use of the HMD 20 is desired to be prevented inputs a replyby guessing.

FIG. 15 is a flowchart illustrating a variant of the process shown inFIG. 14.

In an illustrated example, after step 5111, the determination unit 119determines whether the acquired reply is a correct reply or an incorrectreply and updates a count of the correct replies/incorrect replies (stepS121). The count may be stored, for example, as a numerical value in aRAM or the like. The determination unit 119 then executes step S117.

When it is determined in step S117 that the reproduction of the virtualsound source has been repeated a predetermined number of times, thedetermination unit 119 calculates the number of correct replies of thelistener from the predetermined number of times and the count of thecorrect replies/incorrect replies, and determines whether the number ofcorrect replies or a correct reply rate is equal to or more than athreshold (step S123). Here, when it is determined that the number ofcorrect replies or the correct reply rate is equal to or more than thethreshold, the determination unit 119 determines “unlocking success” andthe locking unit 121 unlocks the HMD 20 to validate the function (stepS119). On the other hand, when it is not determined that the number ofcorrect replies or the correct reply rate is equal to or more than thethreshold, the determination unit 119 determines “unlocking failure” andthe locking unit 121 does not unlock the HMD 20 leaving the functioninvalid (step S115).

In the variant described above, unlocking does not immediately fail, forexample, when there is one incorrect reply during the repetition of thereproduction of the virtual sound source, and the unlocking is likely tooccur when the correct reply is subsequently made. Accordingly, evenwhen the position of the virtual sound source is not necessarily exactlyperceivable every time due to incompleteness of the HRIR function or theheadphone 21 or use of the average HRIR function, it is possible toprevent unlocking by a user himself or herself or a user having apredetermined attribute from failing.

Here, as an additional configuration, the determination unit 119 mayincrease the number of times to repeat the reproduction of the virtualsound source when the incorrect reply is detected in step S121. Forexample, the determination unit 119 may dynamically set the number oftimes to repeat the reproduction of the virtual sound source oncondition that “correct reply is made three consecutive times from thebeginning or after an incorrect reply” or “the reproduction of thevirtual sound source is repeated three times or more, and unlockingsuccess is determined if a correct reply rate is 75% or more on the wayand unlocking failure is determined if the correct reply rate is lessthan 50%.”

(Measurement of Head-Related Transfer Function)

In the first embodiment of the present disclosure described above, thehead-related transfer function data 105 is stored in the functioncontrol apparatus 100 in advance. For example, when the head-relatedtransfer function specific to the user U is used for the above-describedunlocking process, the head-related transfer function is measured forthe user U in advance, for example, using the scheme as described withreference to FIG. 3. In order to acquire a high-precision head-relatedtransfer function, it is desirable to perform the measurement in ananechoic space to remove an influence of reflection on walls. When thehead-related transfer function such as the HRIR is acquired by suchmeasurement, any sound as well as the impulse or the TSP (Time-StretchedPulse) used at the time of the measurement may be used as the originalsound data 111.

However, it is not practical for all users of the HMD 20 to measure thehead-related transfer function in the anechoic space. Therefore, somealternative schemes may be considered. One is to use an averagehead-related transfer function of users having a predetermined attribute(e.g., users who are “adults”) as the head-related transfer function, asdescribed above. In this case, the head-related transfer function iscalculated, for example, based on a result of measuring head-relatedtransfer functions of a sufficient number of samples in the anechoicspace. Therefore, a user of the HMD 20 himself or herself may notmeasure the head-related transfer function. However, for example, whenan average difference is great between shapes of heads of users, theusers may not be recognized as having such an attribute.

Further, the measurement may be performed at a place in which a useruses the HMD 20, such as at home. In this case, for example, amicrophone for noise canceling provided in the same position as theheadphone 21 of the HMD 20 may be used for the measurement. In the caseof a home, since it is not easy to move the position of the sound sourceunlike a dedicated measurement environment, measurement at a pluralityof different sound source positions may be performed, for example,through a movement of a user in a state in which a sound source such asa speaker is fixed to a predetermined position. In this case, in orderfor the user to be able to move to a correct position, a sheet or thelike specifying a positional relationship with the sound source may beincluded in the HMD 20. Alternatively, the measurement may be performedin a state in which a positional relationship between the sound sourceand the HMD 20 is specified, by installing a speaker in a portioncorresponding to a forehead of the user of the HMD 20 or attaching thespeaker with a string to the HMD 20 and moving the speaker in a state inwhich the string is stretched out.

When the measurement is simplified as described above, an influence ofreflection or absorption on walls on a measurement result increases.Further, the accuracy of the position of the sound source at the time ofthe measurement is not high since the position of the sound source isset according to a movement and a manipulation of the user. Therefore,it may be difficult to acquire the head-related transfer function suchas an appropriate HRIR according to a measurement situation. In thiscase, a heard sound of the user, i.e., a sound wave changing accordingto the head-related transfer function, may be measured instead of thehead-related transfer function. If a sound wave recorded near an eardrumof the user when the sound source has been arranged in a certainposition is reproduced near the same eardrum at other times, the userperceives the sound source virtually localized in the position. However,in this case, original sound used at the time of unlocking processing isthe same as the sound reproduced at the time of the measurement.

FIG. 16 is a block diagram illustrating a schematic functionalconfiguration of the function control apparatus according to a variantof the first embodiment of the present disclosure. In this variant, aheard sound of a user is measured in advance instead of a head-relatedtransfer function. Referring to FIG. 16, the function control apparatus160 includes a mounting detection unit 101, a virtual sound sourceposition setting unit 107, a sound data selection unit 163, a decodingcircuit 113, a reproduction unit 115, a reply acquisition unit 117, adetermination unit 119, and a locking unit 121. Further, the functioncontrol apparatus 160 refers to sound data 161 stored in a storagedevice or the like. Hereinafter, the function control apparatus 160 willbe described in connection with a difference with the function controlapparatus 100 shown in FIG. 10 described above.

In the function control apparatus 160, the virtual sound source positionsetting unit 107 provides information of a first set position to thesound data selection unit 163 and the determination unit 119. The sounddata selection unit 163 selects sound data measured by localizing asound source in the first set position from a sound data group measuredby localizing the sound source in a predetermined group of positions ofa virtual acoustic space V with reference to the sound data 161. Theacquired sound data is decoded by the decoding circuit 113 andreproduced by the reproduction unit 115. Thus, in the function controlapparatus 160, for example, a function such as that of the generationunit 109 of the function control apparatus 100 shown in FIG. 10described above is not necessary since stored data is sound data inwhich a head-related transfer function has already been reflected.

(2-2. Second Embodiment)

Next, a second embodiment of the present disclosure will be describedwith reference to FIGS. 17 to 20. The present embodiment differs fromthe first embodiment described above in that the position of the virtualsound source continuously moves during reproduction. Since the presentembodiment is similar to the first embodiment in other points, adetailed description thereof is omitted.

(Configuration of Function Control Apparatus)

FIG. 17 is a block diagram illustrating a schematic functionalconfiguration of a function control apparatus according to a secondembodiment of the present disclosure. Referring to FIG. 17, a functioncontrol apparatus 200 includes a mounting detection unit 101, ahead-related transfer function acquisition unit 103, a virtual soundsource position setting unit 207, a generation unit 209, a decodingcircuit 113, a reproduction unit 115, a line-of-sight input unit 217, adetermination unit 219, and a locking unit 121. Further, the functioncontrol apparatus 200 refers to head-related transfer function data 105and original sound data 111 stored in a storage device or the like.Hereinafter, the function control apparatus 200 will be described inconnection with a difference between the function control apparatus 200and the function control apparatus according to the first embodimentdescribed above.

In the function control apparatus 200, the virtual sound source positionsetting unit 207 sets a first position as a locus. In other words, thevirtual sound source position setting unit 207 sets a position of acontinuously moving virtual sound source during reproduction of sounddata. The head-related transfer function acquisition unit 103 acquires ahead-related transfer function from the head-related transfer functiondata 105 for each position (r, theta, phi) included in the locus of thefirst position, and provides the head-related transfer function to thegeneration unit 209. The generation unit 209 generates sound dataobtained by virtually reproducing the sound source moving in thethree-dimensional acoustic space V using the provided head-relatedtransfer function. More specifically, the generation unit 209 generatesthe sound data obtained by virtually reproducing the moving sound sourceby processing data of the original sound using a different head-relatedtransfer function each time during the reproduction of the sound data.

The line-of-sight input unit 217 continuously acquires a result ofdetecting a line of sight of the user hearing the sound data reproducedby the reproduction unit 115. In other words, the line-of-sight inputunit 217 acquires a movement locus of the line of sight of the user. Themovement locus of the line of sight is treated as a reply indicating thelocus of the sound source estimated by the user hearing the sound dataobtained by virtually reproducing the moving sound source, namely, as alocus of the second position. For the detection of the line of sight ofthe user, for example, cameras arranged in the HMD 20 to recognize theleft eye and the right eye of the user may be used. In this case, theline of sight (gazing point) of the user may be identified, for example,by recognizing a region of the iris and the white of the eyes of theuser from an image of the camera and determining where the iris of theeyes is directed. Further, in addition to this example, variouswell-known technologies may also be used as the configuration fordetecting the line of sight of the user.

The determination unit 219 determines whether the HMD 20 is to beunlocked to validate a function such as content viewing based on arelationship between the locus of the first position set by the virtualsound source position setting unit 207 and the locus of the secondposition acquired by the line-of-sight input unit 217. For example, thedetermination unit 219 may determine that the HMD 20 is to be unlockedif the locus of the first position matches the locus of the secondposition when the sound data is generated using the head-relatedtransfer function of the user U. Further, for example, the determinationunit 219 may determine that the HMD 20 is to be unlocked if an errorbetween the locus of the first position and the locus of the secondposition is within a predetermined range when the sound data isgenerated using the average head-related transfer function of the usershaving a common attribute. Here, for example, well-known technology usedfor pattern recognition of a two-dimensional figure may be used for thematching of the loci and evaluation of the error between the loci.

(Example of Locus of Virtual Sound Source)

FIG. 18 is a diagram illustrating an example of the locus of the virtualsound source in the second embodiment of the present disclosure.Referring to FIG. 18, in the present embodiment, a virtual screen 150similar to that in the first embodiment described above is presented toan observer. In the illustrated example, the locus of the virtual soundsource is set as a straight line in an oblique direction from an upperleft position S_(S) to a lower right position S_(E), when viewed by auser, on the virtual screen 150. Upon hearing a sound, the user followsa position on the virtual screen 150 in which the sound is localizedwith his or her eyes. If the user can correctly perceive the position ofthe virtual sound source, the locus of the line of sight LS may match orbe close to the locus of the virtual sound source.

In the present embodiment, it is determined whether the user correctlyperceives the position of the virtual sound source using the locus inthis way. Since the determination based on a shape of the locus of theline of sight is possible, a coordinate system of the virtual soundsource set on the virtual screen 150 and a coordinate system of the lineof sight of the user acquired by a mechanism such as a camera may notexactly match. In other words, in the illustrated example, it may bedetermined that the user correctly perceives the position of the virtualsound source if the line of sight LS draws a locus from an upper leftregion to a lower right region when viewed by the user, even when theline of sight LS does not exactly draw the locus from a position S_(S)to a position S_(E), in consideration of a deviation of the coordinatesystem or the like. Further, for a similar reason, an image for theposition of the virtual sound source may not be displayed on the virtualscreen 150.

Further, the locus of the virtual sound source to be set is not limitedto the straight line as in the example described above. For example, anyform allowing it to be easily identified that the user follows with hisor her eyes, such as a Z form, an N form, an O form or an L form, may beset as the locus of the virtual sound source.

Further, in the present embodiment, for the user to easily recognize thelocus of the virtual sound source, it is desirable for the head-relatedtransfer function to be prepared for a number of points in a region inwhich the locus is set. For example, it is desirable for a position inwhich the head-related transfer function has been measured to be presentat intervals of 3 degrees to 5 degrees of the deflection angles thetaand phi shown in FIG. 1. As described above, the minimum resolution ofthe user for the deflection angles theta and phi is generally about 3degrees.

As a variant of the present embodiment, the reply of the user may beacquired based on a result of detecting a gesture. For example, a camerafor detecting the gesture of the user may be installed in a portioncorresponding to a forehead of the user of the HMD 20 or in a positionin which the user wearing the HMD 20 can be captured, to continuouslyacquire a result of detecting the gesture of the user when the sounddata is reproduced. In this case, for example, a movement locus of aspecific part (e.g., a hand, a finger or a foot) of a body of the userrecognized as a gesture is treated as a locus of the second position.Further, since well-known technology may be used for the configurationfor detecting the gesture of the user, a detailed description is omittedherein.

(Process Flow)

FIG. 19 is a flowchart illustrating an example of an unlocking processin the second embodiment the present disclosure.

In the present embodiment, in the function control apparatus 200, anunlocking process starts as the mounting detection unit 101 detects thatthe HMD 20 has been mounted by a user, as in the first embodiment (stepS201). First, the virtual sound source position setting unit 207randomly sets the locus of the virtual sound source (step S203). Here,the virtual sound source position setting unit 207, for example,randomly selects the locus from among locus patterns prepared inadvance.

Then, the head-related transfer function acquisition unit 103 acquiresan HRIR function in each position included in the locus of the virtualsound source set in step S203 from among data stored as head-relatedtransfer function data 105 in advance (step S205). Here, the acquiredHRIR function may be, for example, an HRIR function measured in advancefor a specific user and may be an HRIR function provided as an averagehead-related transfer function of users having a predeterminedattribute.

Then, the generation unit 209 generates the sound data of the virtualsound source by performing convolution of the HRIR function acquired instep S205 with original sound data (step S207). Here, the generationunit 209 generates the sound data obtained by virtually reproducing amoving sound source by performing convolution of an HRIR functiondifferent each time with the original sound data. Then, the reproductionunit 115 outputs the sound data to the user through the headphone 21 ofthe HMD 20 (step S209).

Then, the line-of-sight input unit 217 acquires a movement locus of theline of sight of the user while the sound data is being reproduced (stepS211). Here, between step S209 and step S211, a predetermined standbytime may be set in consideration of a time taken for a reaction from auser hearing the sound to the line of sight being moved.

Then, the determination unit 219 determines whether the locus of theline of sight of the user acquired in step S211 matches the locus of thevirtual sound source set in step S203 (step S213). Here, when it is notdetermined that the locus of the line of sight matches the locus of thevirtual sound source, the determination unit 219 determines “unlockingfailure” and the locking unit 121 does not unlock the HMD 20 leaving thefunction invalid (step S215).

On the other hand, when it is determined that the locus of the line ofsight of the user matches the locus of the virtual sound source in stepS213, the determination unit 219 determines whether the reproduction ofthe virtual sound source in steps S203 to S209 has been repeated apredetermined number of times (step S217). Here, when it is determinedthat the reproduction of the virtual sound source has been repeated apredetermined number of times, the determination unit 219 determines“unlocking success” and the locking unit 121 unlocks the HMD 20 tovalidate the function (step S219).

On the other hand, when it is not determined that the reproduction ofthe virtual sound source has been repeated a predetermined number oftimes in step S217, the process of reproducing the virtual sound sourcefrom step S203 is executed again. In this case, in step S203, the locusof the virtual sound source may be randomly set again. Further, thepredetermined number of times may be 1, and in this case, step S217 isnot executed.

In the illustrated example, the reproduction of the virtual sound sourceand the detection of the line of sight of the user are repeated apredetermined number of times while changing the locus of the virtualsound source (although the same locus may be used consecutively as aresult of the random selection). Accordingly, for example, it ispossible to prevent a situation in which unlocking is accidentallyperformed when a child whose use of the HMD 20 is desired to beprevented inputs the line of sight by guessing.

FIG. 20 is a flowchart illustrating a variant of the process shown inFIG. 19.

In an illustrated example, after step S211, the determination unit 219determines whether the acquired locus of the line of sight matches thelocus of the virtual sound source and updates a count of thematching/mismatching (step S221). The count may be stored, for example,as a numerical value in a RAM or the like. The determination unit 219then executes step S217.

When it is determined in step S217 that the reproduction of the virtualsound source has been repeated a predetermined number of times, thedetermination unit 219 calculates the number of times of locus matchingfrom the predetermined number of times and the matching/mismatchingcount and determines whether the number of times of matching or amatching rate is equal to or more than a threshold (step S223). Here,when it is determined that the number of times of matching or thematching rate is equal to or more than a threshold, the determinationunit 219 determines “unlocking success” and the locking unit 121 unlocksthe HMD 20 to validate the function (step S219). On the other hand, whenit is not determined that the number of times of matching or thematching rate is equal to or more than the threshold, the determinationunit 219 determines “unlocking failure” and the locking unit 121 doesnot unlock the HMD 20 leaving the functions invalid (step S215).

In the variant described above, unlocking does not immediately fail, forexample, when there is one locus mismatching during the repetition ofthe reproduction of the virtual sound source, and the unlocking islikely to occur when the locus matching subsequently occurs.Accordingly, even when the locus of the virtual sound source is notnecessarily exactly perceivable every time due to incompleteness of theHRIR function or the headphone 21 or use of the average HRIR function,it is possible to prevent unlocking by a user himself or herself or auser having a predetermined attribute from failing.

Here, as an additional configuration, the determination unit 219 mayincrease the number of times to repeat the reproduction of the virtualsound source when the incorrect reply is detected in step S221. Forexample, the determination unit 219 may dynamically set the number oftimes to repeat the reproduction of the virtual sound source oncondition that “loci match three consecutive times from the beginning orafter an incorrect reply” or “the reproduction of the virtual soundsource is repeated three times or more, and unlocking success isdetermined if a correct reply rate is 75% or more on the way andunlocking failure is determined if the correct reply rate is less than50%.”

(Application Example)

In the present embodiment, the image may not be displayed on the virtualscreen in unlocking using the virtual sound source. Using this, variousapplication examples are possible.

For example, the present embodiment may be applied when an AR (AugmentedReality) application is used in the HMD. In the AR application, forexample, various pieces of information are superimposed and displayed onan image of an external world viewed through transmission in asee-through type HMD or an image of an external world imaged using acamera mounted on a non-see-through type HMD.

Such an AR application includes an AR application that can bemanipulated by the line of sight of the user. In this case, for example,when a user gazes at any one of pieces of displayed information, furtherdetailed information on such information is presented. Further, forexample, an icon for starting up another function such as transmissionand reception of a message may be displayed on an edge of the screenseparately from the information on the image of the external world, andthe AR application may stop to start the other function by the usergazing at the icon.

In this case, when the other function has been set to immediately startup according to gazing of the user, malfunction is likely to occur. Forexample, when the user follows a moving object and moves the line ofsight to the edge of the screen, a message function is likely to startup due to the line of sight accidentally hitting an icon for the messagefunction displayed there. Then, although not intended, the ARapplication stops and the user feels discomfort. In order to preventthis, for example, displaying a confirmation dialog when gazing at theicon may be considered, but it may not be said that it is the best forthe user since the display of the confirmation dialog also interfereswith the AR application.

Here, application of the present embodiment is considered. For example,when the line of sight of the user hits an icon for another functionsuch as a message during start-up of the AR application, the unlockingprocess as described above is executed. In other words, when the line ofsight of the user hits the icon for a function, the virtual sound sourceis reproduced while moving along a predetermined locus. If the userreally gazes at the icon with the intention of starting up of thefunction, the user may follow the locus of the virtual sound source withhis or her eyes. Then, the function is validated by matching of thelocus of the line of sight and the locus of the virtual sound source,and the AR application stops. On the other hand, if the user does notintend to start up the function, the user may neglect reproduced sound.Then, since the locus of the line of sight and the locus of the virtualsound source do not match, the function is not validated and the ARapplication is continuously executed.

According to the example described above, the user can confirm whetherthe other function is to start up without stopping the display of the ARapplication. Therefore, it is possible to comfortably enjoy the ARapplication while securing access to other functions through the displayof the icon.

Similarly, the present embodiment may be applied to an AR applicationthat may be manipulated by the gesture of the user. For example, thereis an AR application that operates by recognizing the gesture of theuser as a command using a camera provided in a portion corresponding tothe forehead of the user of the HMD, or the like. In this case, forexample, when a predetermined part of a body of the user such as thehand is recognized by the camera and a predetermined motion isperformed, the AR application stops and another function such astransmission and reception of a message starts up.

In this case, if another function is set to start up immediately whenthe hand of the user is captured by the camera or a predetermined motionis performed, malfunction is likely to occur. For example, if the handof the user is accidentally captured by the camera or a motion of thehand accidentally matches a predetermined motion when the user raiseshis or her hand to greet a friend, the AR application is likely to stopand another function such as a message function is likely to start upagainst the intention of the user. Like the example described above,correspondence of displaying a confirmation dialog may be considered,but it is not the best for a user to interfere with the indication ofthe AR application of the indication of the confirmation dialog.

Therefore, if the present embodiment is applied, the unlocking processas described above is executed, for example, when the hand of the useris captured by the camera or a predetermined motion of the hand isperformed during start-up of the AR application. In other words, whenthe hand of the user or the motion of the hand is recognized, thevirtual sound source is reproduced while moving along a predeterminedlocus. If the user really performs a gesture with the intention of thestart-up of the function, the gesture of the hand should follow thelocus of the virtual sound source. Then, the function is validated bymatching of the locus of the hand of the user and the locus of thevirtual sound source, and the AR application stops. On the other hand,if the user does not intend the start-up of the function, the user mayneglect reproduced sound. Then, since the locus of the hand of the userand the locus of the virtual sound source do not match, the function isnot validated and the AR application is continuously executed.

Further, a similar application example is possible in applications otherthan the AR application. For example, even in viewing of content of amovie or the like or in a game, a manipulation input using the line ofsight or the gesture may be implemented. In this case, for example, theunlocking process as described above may be executed in order to reallyconfirm whether the function is to really start up when execution of acommand input by the line of sight or the gesture (gazing of apredetermined position within the screen, detection of an image of thehand or the like of the user, a predetermined detected motion of thehand, or the like) is accompanied by stop of viewing of content orplaying of the game.

Here, if sound not related at all is reproduced as the virtual soundsource when viewing of provided content or an application such as a gameis accompanied by sound, interfering with the application may beconsidered. Therefore, for example, the sound of the application may betemporarily monaurally reproduced and the sound itself may be reproducedas the virtual sound source along a predetermined locus. By doing so,the unlocking process can be executed without sound other than the soundof the application being mixed. Further, it is desirable to prepare foran environment for measurement and acquire the head-related transferfunction with high precision in order to execute the reproduction of thevirtual sound source using any sound source, as described above.

(2-3. Third Embodiment)

Next, a third embodiment of the present disclosure will be describedwith reference to FIGS. 21 and 22. The present embodiment differs fromthe first and second embodiments described above in that the virtualsound source is reproduced for any selected user attribute. Since thepresent embodiment is similar to the first embodiment or the secondembodiment in other points, a detailed description thereof is omitted.Further, in the following description, an example based on the firstembodiment will be described, but an example based on the secondembodiment is similarly possible.

(Configuration of Function Control Apparatus)

FIG. 21 is a block diagram illustrating a schematic configuration of afunction control apparatus according to the third embodiment of thepresent disclosure. Referring to FIG. 21, the function control apparatus300 includes a user attribute setting unit 301, a head-related transferfunction acquisition unit 303, a virtual sound source position settingunit 107, a generation unit 109, a decoding circuit 113, a reproductionunit 115, a reply acquisition unit 117, a determination unit 119, and alocking unit 121. Further, the function control apparatus 300 refers tohead-related transfer function data 305 and original sound data 111stored in a storage device or the like. Hereinafter, the functioncontrol apparatus 300 will be described in connection with a differencebetween the function control apparatus 300 and the function controlapparatus according to the first embodiment described above.

The user attribute setting unit 301 sets an attribute of a user used forunlocking and provides information of the set attribute to thehead-related transfer function acquisition unit 303. The head-relatedtransfer function acquisition unit 303 acquires a head-related transferfunction associated with a designated attribute with reference to thehead-related transfer function data 305. Here, the acquired head-relatedtransfer function may be a head-related transfer function provided as anaverage head-related transfer function of a user group having a commonattribute. In the present embodiment, the head-related transfer functiondata is prepared for a plurality of attributes in advance, and thehead-related transfer function acquisition unit 303 selects thehead-related transfer function corresponding to the attribute set by theuser attribute setting unit 301 from among the plurality of attributes.

As a difference between the first and second embodiments described aboveand the present embodiment, unlocking is executed using the head-relatedtransfer function (e.g., an original head-related transfer function of auser of the HMD 20 or an average head-related transfer function of usershaving an attribute “adult”) determined in advance in the first andsecond embodiments, whereas in the present embodiment, an attribute usedfor unlocking is selected from among a plurality of attributes. In otherwords, in the present embodiment, the user attribute setting unit 301may select, for example, a target attribute from among a plurality ofattributes, such as “16 years or older,” “18 years or older” or “20years or older” in response to a manipulation input of the user and arequest from an application. A head-related transfer functioncorresponding to each of selectable attributes is included in thehead-related transfer function data 305.

As a specific use example of such a configuration, for example, the userattribute setting unit 301 may set an attribute “16 years or older” (anage in which viewing of content using the HMD is considered not toaffect health) at the time of starting up or mounting of the HMD 20.Further, when content whose rating has been set is reproduced in the HMD20, the user attribute setting unit 301 may set an attribute (e.g., “18years or older”) according to the rating. By doing this, it is possibleto limit viewing of content using the HMD 20 to the HMD itself or usersmore suitable for the content.

Alternatively, the user attribute setting unit 301 may recognize theattribute of the user of the HMD 20 by setting a plurality of attributesat the time of start-up of the HMD 20 and executing reproduction of thevirtual sound source corresponding to each attribute. For example, theuser attribute setting unit 301 may set attributes of “adult,” “child,”“male” and “female” at the time of starting up or mounting of the HMD20. In this case, in the units subsequent to the head-related transferfunction acquisition unit 303, the sound data of the virtual soundsource generated using the head-related transfer functions for therespective attributes described above are all continuously reproduced orat least some of the sound data is simultaneously reproduced (e.g.,sound data for “adult” and “child” is simultaneously reproduced, andsound data “male” and “female” is simultaneously reproduced). In thiscase, the virtual sound source position setting unit 107 sets adifferent position (or position pattern or locus) for each attribute asa position of the virtual sound source. The attribute of the user may beidentified according to which attribute corresponding to a position withwhich the user hearing the sound data of the virtual sound sourcereproduced in this way replies. For example, if sound data correspondingto paired attributes (e.g., “adult” and “child”) are simultaneouslyreproduced, it is possible to easily identify the attribute of the usersince the position corresponding to any one attribute is selectivelyreplied.

In the above example, a result of identifying the attribute for age maybe used, for example, to determine whether the HMD 20 itself isavailable or whether viewing of content is allowed. Further, a result ofidentifying the attribute for sex may be used, for example, forrecommendation of content and display of an advertisement.

(Process Flow)

FIG. 22 is a flowchart illustrating an example of an unlocking processin the third embodiment of the present disclosure.

First, the user attribute setting unit 301 sets an attribute of a userused for an unlocking process (step S301). Then, the virtual soundsource position setting unit 107 randomly sets the position of thevirtual sound source (step S303). Here, the virtual sound sourceposition setting unit 107 randomly selects, for example, the position ofthe virtual sound source from among the above-described positions S₁ toS₉. When the user attribute setting unit 301 sets a plurality ofattributes, the virtual sound source position setting unit 107 may set adifferent position for each attribute.

Then, the head-related transfer function acquisition unit 303 acquiresan HRIR function corresponding to the attribute set in step S301 in theposition of the virtual sound source set in step S303 from among thedata stored as the head-related transfer function data 305 in advance(step S305). Here, the acquired HRIR function may be an HRIR functionprovided as an average head-related transfer function of users having apredetermined attribute in advance.

Then, the generation unit 109 generates the sound data of the virtualsound source by performing convolution of the HRIR function acquired instep S305 with original sound data (step S307). Then, the reproductionunit 115 outputs the sound data to the user through the headphone 21 ofthe HMD 20 (step S309). Here, when the user attribute setting unit 301sets a plurality of attributes, the reproduction unit 115 maycontinuously output the sound data corresponding to each attribute ormay simultaneously output the sound data corresponding to at least someof the attributes.

Then, the reply acquisition unit 117 acquires the reply indicating theposition of the virtual sound source estimated by the user through themanipulation unit 23 of the HMD 20 (step S311). Here, a predeterminedstandby time may be set in consideration of a time taken for a thoughtand a movement of the user between step S309 and step S311. Further,when a plurality of pieces of sound data are continuously output in stepS309, a reply for each piece of sound data may be acquired.

For example, when the sound data corresponding to the attributes of“adult” and “child” is simultaneously reproduced and subsequently thesound data corresponding to the attributes of “male” and “female” issimultaneously reproduced in step S309, the reply acquisition unit 117can acquire a first reply (used to identify whether the user is “adult”or “child”) and a second reply (used to identify whether the user is“male” or “female”).

Then, the determination unit 119 determines whether the positionindicated by the reply acquired in step S311 (the second position)matches the position of the virtual sound source set in step S303 (thefirst position) (step S313). Further, when a plurality of attributes areset in step S301, the determination herein may be executed for eachattribute. In this case, at least one (e.g., “adult” or “child”) of theset attributes is used for the determination as to whether or not thefunction of the HMD 20 is to be unlocked in step S313. Attributes notused for this determination are subjected to an attribute suitabilitydetermination for other processes, and provided, for example, asinformation for recommendation of content, display of an advertisementor the like.

When it is not determined in step S313 described above that thepositions match, the determination unit 119 determines “unlockingfailure” and the locking unit 121 leaves the function invalid (stepS315). The function cited herein may be, for example, all functions ofthe HMD as in the first embodiment described above or may be a functionof viewing some content protected depending on age.

On the other hand, when it is determined in step S313 that the positionshown by the replay matches the position of the virtual sound source,the determination unit 119 further determines whether the reproductionof the virtual sound source in steps S303 to S309 is repeated apredetermined number of times (step S317). Here, when sound sourcescorresponding to a plurality of attributes are reproduced, the number oftimes to be set may differ for each attribute.

When it is determined in step S317 that the reproduction of the virtualsound source has been repeated a predetermined number of times, thedetermination unit 119 determines “unlocking success” and the lockingunit 121 validates the function (step S319). On the other hand, when itis not determined that the reproduction of the virtual sound source hasbeen repeated a predetermined number of times, the process ofreproducing the virtual sound source from step S303 is executed again.In this case, in step S303, the position of the virtual sound source maybe randomly set again. Further, the predetermined number of times may be1 and, in that case, step S317 is not executed.

Further, although not shown, even in the present embodiment, a variantin which the reproduction of the virtual sound source is repeated apredetermined number of times regardless of a correct reply or anincorrect reply, the attribute of the user is determined based on thecorrect reply rate during the reproduction, and lock is released, asdescribed with reference to FIG. 15 in the first embodiment, ispossible. Further, a configuration in which the virtual sound sourceposition setting unit sets the locus of the virtual sound source, thegeneration unit generates the sound data obtained by virtuallyreproducing the moving sound source, and the reply acquisition unitacquires the reply of the user based on the line of sight or the gestureof the user, as described with reference to FIGS. 19 and 20 in thesecond embodiment, is possible.

In the third embodiment of the present disclosure described above, it ispossible to control, for example, locking/unlocking corresponding to agelimitation of provided content, as well as locking/unlocking at the timeof starting-up or mounting of the HMD, by allowing the attribute to bearbitrarily set. Further, information on an attribute for being used forother uses, as well as the attribute used for lock control, can beacquired.

(2-4. Fourth Embodiment)

Next, a fourth embodiment of the present disclosure will be describedwith reference to FIGS. 23 and 24. This embodiment differs from thefirst and second embodiments described above in that the virtual soundsource is reproduced for any selected user ID. Since the presentembodiment is similar to the first embodiment or the second embodimentin other points, a detailed description thereof is omitted. Further,while an example based on the first embodiment will be described in thefollowing description, an example based on the second embodiment issimilarly possible.

(Configuration of Function Control Apparatus)

FIG. 23 is a block diagram illustrating a schematic configuration of afunction control apparatus according to a fourth embodiment of thepresent disclosure. Referring to FIG. 23, the function control apparatus400 includes a user ID setting unit 401, a head-related transferfunction acquisition unit 403, a virtual sound source position settingunit 107, a generation unit 109, a decoding circuit 113, a reproductionunit 115, a reply acquisition unit 117, a determination unit 119 and alocking unit 121. Further, the function control apparatus 400 refers tohead-related transfer function data 405 and original sound data 111stored in a storage device or the like. Hereinafter, the functioncontrol apparatus 400 will be described in connection with a differencebetween the function control apparatus 400 and the function controlapparatus according to the first embodiment described above.

The user ID setting unit 401 sets an ID of a user used for unlocking andprovides information of the set ID to the head-related transfer functionacquisition unit 403. The head-related transfer function acquisitionunit 403 acquires a head-related transfer function associated with thedesignated ID with reference to the head-related transfer function data405. Here, the acquired head-related transfer function may be ahead-related transfer function measured for a user corresponding to theID in advance. In the present embodiment, the data of the head-relatedtransfer function is prepared for a plurality of IDs in advance, and thehead-related transfer function acquisition unit 403 selects thehead-related transfer function corresponding to the ID set by the userID setting unit 401 from among the plurality of IDs.

As a difference between the first and second embodiments described aboveand the present embodiment, unlocking is executed using the head-relatedtransfer function determined in advance in the first and secondembodiments, whereas in the present embodiment, an ID used for unlockingis selected from a plurality of user IDs. In other words, in the presentembodiment, the user ID setting unit 401 may select a target user IDfrom the plurality of user IDs, for example, in response to amanipulation input of the user or a request from an application. Ahead-related transfer function corresponding to each of selectable userIDs may be included in the head-related transfer function data 405.

As a specific use example of such a configuration, for example, the userID setting unit 401 displays a list of users registered as users at thetime of start-up or mounting of the HMD 20 and sets the ID of the userselected from the list by manipulation input as an ID of a user used forunlocking. Accordingly, the function can be unlocked through theunlocking process using a virtual sound source executed later only for auser corresponding to the user ID. Alternatively, when access to afunction of reproducing personal content (including a message or thelike) or paid content allowed to be accessed by only a specific user isnecessary during start-up of the HMD 20, the user ID setting unit 401may perform the unlocking process using a user ID permitted to accessthe content.

Such a configuration is effective, for example, when personal contentthat can be reproduced is limited to personal content of a user that isan unlocking target at the time of start-up or mounting in a case inwhich the HMD 20 can reproduce personal content of each user. Further,when the user ID and age, sex or the like of the user have beenassociated, a setting of validity/invalidity of content reproductionaccording to the age of the user, recommendation of content according tothe attribute of the user, display of an advertisement according to theattribute of the user, or the like becomes possible. Further, when theHMD 20 can reproduce paid content, a function of reproducing the contentmay be validated for only a user purchasing the paid content.

(Process Flow)

FIG. 24 is a flowchart illustrating an example of an unlocking processin the fourth embodiment of the present disclosure.

First, the user ID setting unit 401 sets a user ID used for theunlocking process (step S401). Then, the virtual sound source positionsetting unit 107 randomly sets the position of the virtual sound source(step S403). Here, the virtual sound source position setting unit 107randomly selects the position of the virtual sound source from theabove-described positions S₁ to S₉.

Then, the head-related transfer function acquisition unit 403 acquiresan HRIR function corresponding to the user ID set in step S401 in theposition of the virtual sound source set in step S403 from among thedata stored as the head-related transfer function data 405 in advance(step S405). Here, the acquired HRIR function may be an HRIR functionmeasured for a user associated with the ID in advance.

Since a subsequent process (steps S107 to S119) is similar to theprocess described with reference to FIG. 14 in the first embodiment, adetailed description thereof is omitted. Further, although not shown,even in the present embodiment, a variant in which the reproduction ofthe virtual sound source is repeated a predetermined number of timesregardless of a correct reply or an incorrect reply, the attribute ofthe user is determined based on the correct reply rate during thereproduction, and lock is released, as described with reference to FIG.15 in the first embodiment, is possible. Further, a configuration inwhich the virtual sound source position setting unit sets the locus ofthe virtual sound source, the generation unit generates the sound dataobtained by virtually reproducing the moving sound source, and the replyacquisition unit acquires the reply of the user based on the line ofsight or the gesture of the user, as described with reference to FIGS.19 and 20 in the second embodiment, is possible.

In the fourth embodiment of the present disclosure described above, itis possible to control, for example, locking/unlocking corresponding toa holder, use authority or the like of provided content, as well aslocking/unlocking at the time of start-up or mounting of the HMD, byallowing the user ID to be arbitrarily set.

(3. Hardware Configuration)

Next, a hardware configuration of the information processing apparatusaccording to an embodiment of the present disclosure will be describedwith reference to FIG. 25. FIG. 25 is a block diagram illustrating ahardware configuration of the information processing apparatus. Theillustrated information processing apparatus 900 may realize, forexample, the function control apparatus in the embodiments describedabove.

The information processing apparatus 900 includes a CPU (CentralProcessing Unit) 901, a ROM (Read Only Memory) 903, and a RAM (RandomAccess Memory) 905. In addition, the information processing apparatus900 may include a host bus 907, a bridge 909, an external bus 911, aninterface 913, an input device 915, an output device 917, a storagedevice 919, a drive 921, a connection port 923, and a communicationdevice 925. Further, the information processing apparatus 900 mayinclude an imaging device 933 and a sensor 935 as necessary. Theinformation processing apparatus 900 may include a processing circuitsuch as a DSP (Digital Signal Processor), alternatively or in additionto the CPU 901.

The CPU 901 serves as an operation processor and a controller, andcontrols all or some operations in the information processing apparatus900 in accordance with various programs recorded in the ROM 903, the RAM905, the storage device 919 or a removable recording medium 927. The ROM903 stores programs and operation parameters which are used by the CPU901. The RAM 905 primarily stores program which are used in theexecution of the CPU 901 and parameters which is appropriately modifiedin the execution. The CPU 901, ROM 903, and RAM 905 are connected toeach other by the host bus 907 configured to include an internal bussuch as a CPU bus. In addition, the host bus 907 is connected to theexternal bus 911 such as a PCI (Peripheral ComponentInterconnect/Interface) bus via the bridge 909.

The input device 915 may be a device which is operated by a user, suchas a mouse, a keyboard, a touch panel, buttons, switches and a lever.The input device 915 may be, for example, a remote control unit usinginfrared light or other radio waves, or may be an external connectiondevice 929 such as a portable phone operable in response to theoperation of the information processing apparatus 900. Furthermore, theinput device 915 includes an input control circuit which generates aninput signal on the basis of the information which is input by a userand outputs the input signal to the CPU 901. By operating the inputdevice 915, a user can input various types of data to the informationprocessing apparatus 900 or issue instructions for causing theinformation processing apparatus 900 to perform a processing operation.

The output device 917 includes a device capable of visually or audiblynotifying the user of acquired information. The output device 917 mayinclude a display device such as LCD (Liquid Crystal Display), PDP(Plasma Display Panel), and organic EL (Electro-Luminescence) displays,an audio output device such as speaker and headphone, and a peripheraldevice such as printer. The output device 917 may output the resultsobtained from the process of the information processing apparatus 900 ina form of a video such as text or image, and an audio such as voice orsound.

The storage device 919 is a device for data storage which is configuredas an example of a storage unit of the information processing apparatus900. The storage device 919 includes, for example, a magnetic storagedevice such as HDD (Hard Disk Drive), a semiconductor storage device, anoptical storage device, or a magneto-optical storage device. The storagedevice 919 stores programs to be executed by the CPU 901, various data,and data obtained from the outside.

The drive 921 is a reader/writer for the removable recording medium 927such as a magnetic disk, an optical disk, a magneto-optical disk, or asemiconductor memory, and is embedded in the information processingapparatus 900 or attached externally thereto. The drive 921 readsinformation recorded in the removable recording medium 927 attachedthereto, and outputs the read information to the RAM 905. Further, thedrive 921 can write in the removable recording medium 927 attachedthereto.

The connection port 923 is a port used to directly connect devices tothe information processing apparatus 900. The connection port 923 mayinclude a USB (Universal Serial Bus) port, an IEEE1394 port, and a SCSI(Small Computer System Interface) port. The connection port 923 mayfurther include an RS-232C port, an optical audio terminal, an HDMI(High-Definition Multimedia Interface) port, and so on. The connectionof the external connection device 929 to the connection port 923 makesit possible to exchange various data between the information processingapparatus 900 and the external connection device 929.

The communication device 925 is, for example, a communication interfaceincluding a communication device or the like for connection to acommunication network 931. The communication device 925 may be, forexample, a communication card for a wired or wireless LAN (Local AreaNetwork), Bluetooth (registered trademark), WUSB (Wireless USB) or thelike. In addition, the communication device 925 may be a router foroptical communication, a router for ADSL (Asymmetric Digital SubscriberLine), a modem for various kinds of communications, or the like. Thecommunication device 925 can transmit and receive signals to and from,for example, the Internet or other communication devices based on apredetermined protocol such as TCP/IP. In addition, the communicationnetwork 931 connected to the communication device 925 may be a networkor the like connected in a wired or wireless manner, and may be, forexample, the Internet, a home LAN, infrared communication, radio wavecommunication, satellite communication, or the like.

The imaging device 933 is a device that generates an image by imaging areal space using an image sensor such as a charge-coupled device (CCD)or complementary metal-oxide-semiconductor (CMOS) sensor, as well asvarious members such as one or more lenses for controlling the formationof a subject image on the image sensor, for example. The imaging device933 may be a device that takes still images, and may also be a devicethat takes moving images.

The sensor 935 is any of various sensors such as an acceleration sensor,a gyro sensor, a geomagnetic sensor, an optical sensor, or a soundsensor, for example. The sensor 935 acquires information regarding thestate of the information processing apparatus 900, such as theorientation of the case of the information processing apparatus 900, aswell as information regarding the environment surrounding theinformation processing apparatus 900, such as the brightness or noisesurrounding the information processing apparatus 900, for example. Thesensor 935 may also include a Global Positioning System (GPS) sensorthat receives GPS signals and measures the latitude, longitude, andaltitude of the apparatus.

The foregoing thus illustrates an exemplary hardware configuration ofthe information processing apparatus 900. Each of the above componentsmay be realized using general-purpose members, but may also be realizedin hardware specialized in the function of each component. Such aconfiguration may also be modified as appropriate according to thetechnological level at the time of the implementation.

(4. Supplemental Remarks)

Embodiments of the present disclosure encompass a function controlapparatus (an information processing apparatus) and system as describedin the foregoing, a function control method executed by a functioncontrol apparatus or system, a program for causing a function controlapparatus to function, and a non-transitory computer readable mediumstoring such a program, for example.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

Additionally, the present technology may also be configured as below.

-   (1) An electronic device including-   processing circuitry configured to-   produce an audio sound from a virtual sound source position;-   acquire from a user-input a sound position information of a    perceived sound source position; and-   control an enable or disable of a function of the electronic device    based on a relationship between the virtual sound source position    and the perceived sound source position.-   (2) The electronic device of (1), wherein-   the processing circuitry is further configured to determine whether    to enable or disable the function.-   (3) The electronic device of (1), wherein-   the processing circuitry being a single CPU that performs processing    to determine whether to enable or disable the function.-   (4) The electronic device of (1), wherein-   the virtual sound source position is generated based on a    head-related transfer function, HRTF.-   (5) The electronic device of (4), wherein-   the HRTF is user-specific, and includes-   a right function HRTF_R that depends on the user U, moving radius r,    and deflections angles theta and phi, and expressed as HRTF_R(U, r,    theta, phi), and a left function HRTF_L expressed as LRTF_L(U, r,    theta, phi).

(6) The electronic device of (5), wherein

-   the processing circuitry is configured to produce a head-related    impulse response, HRIR, by performing an inverse discrete Fourier    transform on the HRTF.

(7) The electronic device of (6), wherein

-   HRIR having a left component expressed as HRIR_L(U, r, theta, phi)    and a right components expressed as HRIR_R(U, r, theta, phi).

(8) The electronic device of (7), wherein the processing circuitry isconfigured to produce the audio sounds as

-   an output acoustic signal to a left ear of the user, YL, and-   an output acoustic signal a right ear of the user YR, wherein YL and    YR are generated by a convolution, *, of HRIR_L(U, r, theta, phi),    and HRIR_R(U, r, theta, phi) with an original sound X according to    Y _(L) =X*HRIR_L(U, r, θ, φ)   (Equation 1)    Y _(R) =X*HRIR_R(U, r, θ, φ)   (Equation 2).-   (9) The electronic device of (1), further including-   a head mounted display configured to be worn on a head of a user and    having left and right speakers configured to produce sound in left    and right ears of the user.-   (10) The electronic device of (1), wherein-   the processing circuitry-   selects the virtual sound source position from one of a plurality of    different virtual sound source positions, and-   compares the virtual sound source position to the perceived sound    source position information acquired from the user-input, and-   controls the enable of the function of the electronic device when    the processing circuitry determines that the perceived sound source    position is a closer match to the virtual sound source position than    any other of the plurality of different virtual source positions.-   (11) The electronic device of (10), wherein-   the function is an unlock function that unlocks the electronic    device for use.-   (12) The electronic device of (4), wherein-   the HRTF is an average head-related transfer function of users    having a common attribute.-   (13) The electronic device of (12),-   the function is an unlock function that unlocks the electronic    device for use.-   (14) The electronic device of (1), further including-   a head mounted display configured to be worn on a head of a user and    having a display, wherein-   the processing circuitry-   selects the virtual sound source position from one of a plurality of    different virtual sound source positions, and-   displays indicia associated with the plurality of different virtual    sound source positions.-   (15) The electronic device of (1), wherein-   the processing circuitry is configured to move the virtual sound    source position while the processing circuitry acquires the    user-input for the sound position information for a plurality of    perceived sound source positions.-   (16) The electronic device of (15), further including-   a line-of-sight input unit that identifies the user-input for the    sound position information by tracking a line-of-sight of a user on    a displayed image.-   (17) The electronic device of (1), wherein-   the processing circuitry is configured to reproduce the audio sound    of the virtual source corresponding to a user selectable attribute.-   (18) The electronic device of (1), wherein-   the processing circuitry associates IDs for a plurality of different    users,-   the user-input also identifies a particular user from the plurality    of different users, and-   the function is an unlock function that unlocks the electronic    device for use when and ID for the particular user is selected and    there is a match between the virtual sound source position and    perceived sound source position for that particular user.-   (19) An information processing method including-   producing with a speaker an audio sound from a virtual sound source    position;-   acquiring from a user-input interface a sound position information    of a perceived sound source position; and-   controlling with processing circuitry an enable or disable of a    function of the electronic device based on a relationship between    the virtual sound source position and the perceived sound source    position.-   (20) A non-transitory computer readable storage medium having stored    therein computer readable instructions that when executed by    processing circuitry cause the processing circuitry to execute an    information processing method, the method including-   producing with a speaker an audio sound from a virtual sound source    position;-   acquiring from a user-input interface a sound position information    of a perceived sound source position; and-   controlling with the processing circuitry an enable or disable of a    function of the electronic device based on a relationship between    the virtual sound source position and the perceived sound source    position.

Additionally, the present technology may also be configured as below.

(1)

A function control apparatus including:

-   a reproduction unit that reproduces, toward a user, sound data    obtained by virtually localizing a sound source present in a first    position of a space around the user using a head-related transfer    function;-   an estimated position information acquisition unit that acquires    information indicating a second position of the space around the    user, the second position being estimated as a position of the sound    source by the user hearing the reproduced sound data; and-   a determination unit that determines whether at least some functions    of an electronic device are to be validated, based on a relationship    between the first position and the second position.

(2)

The function control apparatus according to (1), wherein

-   the head-related transfer function is a head-related transfer    function corresponding to the user, and-   the determination unit determines that the at least some functions    are to be validated, when the first position and the second position    match.

(3)

The function control apparatus according to (2), wherein

-   the determination unit determines that a function of reproducing    content permitted to be accessed by the user is to be validated,    when the first position and the second position match.

(4)

The function control apparatus according to (1), wherein

-   the head-related transfer function is a first head-related transfer    function corresponding to a user group having a first attribute, and-   the determination unit determines that the at least some functions    are to be validated, when it is estimated that the user has the    first attribute based on a relationship between the first position    and the second position.

(5)

The function control apparatus according to (4), wherein

-   the reproduction unit reproduces, toward the user, first sound data    obtained by virtually localizing the sound source using the first    head-related transfer function, and second sound data obtained by    virtually localizing the sound source using a second head-related    transfer function corresponding to a user group having a second    attribute different from the first attribute, and-   the determination unit determines whether the user has the first    attribute or the second attribute, based on whether the second    position corresponds to the first position of any one of the first    sound data and the second sound data.

(6)

The function control apparatus according to any one of (1) to (5),wherein

-   the estimated position information acquisition unit acquires a    result of detecting a line of sight of the user as the information    indicating the second position.

(7)

The function control apparatus according to any one of (1) to (5),wherein

-   the estimated position information acquisition unit acquires a    result of detecting a gesture of the user as the information    indicating the second position.

(8)

The function control apparatus according to any one of (1) to (5),wherein

-   the first position continuously moves during reproduction of the    sound data, the estimated position information acquisition unit    continuously acquires the information indicating the second    position, and-   the determination unit determines whether the at least some    functions are to be validated, based on a relationship between a    locus of the first position and a locus of the second position.

(9)

The function control apparatus according to (8), wherein

-   the estimated position information acquisition unit continuously    acquires a result of detecting a line of sight of the user as the    information indicating the second position.

(10)

The function control apparatus according to (8), wherein

-   the estimated position information acquisition unit continuously    acquires a result of detecting a gesture of the user as the    information indicating the second position.

(11)

The function control apparatus according to any one of (1) to (7),wherein

-   the first position is any one position in a position group    determined in advance in the space around the user.

(12)

The function control apparatus according to any one of (1) to (11),wherein

-   the reproduction unit repeats reproduction of the sound data a    predetermined number of times,-   the estimated position information acquisition unit repeats    acquisition of the information indicating the second position the    predetermined number of times, and-   the determination unit determines that the at least some functions    are to be validated, when a number of times the first position and    the second position have met a predetermined relationship is equal    to or more than a threshold during repetition of the predetermined    number of times.

(13)

The function control apparatus according to any one of (1) to (12),further including:

-   a generation unit that generates the sound data.

(14)

The function control apparatus according to any one of (1) to (12),further including:

-   a sound data selection unit that selects the sound data from a sound    data group localized in a predetermined position group of the space    around the user and provides the sound data to the reproduction    unit.

(15)

The function control apparatus according to any one of (1) to (14),wherein

-   the electronic device is a head mount display, and-   the determination unit determines that a content reproduction    function of the head mount display is to be validated when the user    is estimated to be at a predetermined age or older, based on a    relationship between the first position and the second position.

(16)

The function control apparatus according to (15), wherein

-   the reproduction unit reproduces the sound data through a headphone    of the head mount display.

(17)

The function control apparatus according to (15) or (16), furtherincluding:

-   a mounting detection unit that detects that the head mount display    has been mounted by the user,-   wherein the reproduction unit reproduces the sound data when the    mounting detection unit detects that the head mount display has been    mounted.

(18)

A program for causing a computer to realize functions of:

-   reproducing, toward a user, sound data obtained by virtually    localizing a sound source present in a first position of a space    around the user using a head-related transfer function;-   acquiring information indicating a second position of the space    around the user, the second position being estimated as a position    of the sound source by the user hearing the reproduced sound data;    and-   determining whether at least some functions of an electronic device    are to be validated, based on a relationship between the first    position and the second position.

REFERENCE SIGNS LIST

-   20 head mount display (HMD)-   21 headphone-   22 display unit-   23 manipulation unit-   30 converter-   40 system-   100, 160, 200, 300, 400 function control apparatus-   101 mounting detection unit-   103, 303, 403 head-related transfer function acquisition unit-   107, 207 virtual sound source position setting unit-   109, 209 generation unit-   115 reproduction unit-   117 reply acquisition unit-   119, 219 determination unit-   121 locking unit-   163 sound data selection unit-   217 line-of-sight input unit-   301 user attribute setting unit-   401 user ID setting unit

The invention claimed is:
 1. An electronic device, comprising: processing circuitry configured to: acquire an attribute of a first user of the electronic device; produce an audio sound from a virtual sound source position based on a function that is determined based on the virtual sound source position and the acquired attribute; acquire from an input by the first user, position information of a perceived sound source position; and control a functionality of the electronic device based on a relationship between the virtual sound source position and the position information of the perceived sound source position.
 2. The electronic device of claim 1, wherein the processing circuitry is further configured to determine whether to enable or disable the functionality.
 3. The electronic device of claim 1, wherein the processing circuitry is a central processing unit (CPU) configured to determine whether to enable or disable the functionality.
 4. The electronic device of claim 1, wherein the function is a head-related transfer function, HRTF.
 5. The electronic device of claim 4, wherein the HRTF includes: a right function HRTF_R that depends on the first user U, a moving radius r, and deflection angles theta and phi, and is expressed as HRTF_R(U, r, theta, phi); and a left function HRTF_L expressed as LRTF_L(U, r, theta, phi).
 6. The electronic device of claim 5, wherein the processing circuitry is further configured to produce a head-related impulse response, HRIR, based on an inverse discrete Fourier transform of the HRTF.
 7. The electronic device of claim 6, wherein the HRIR comprises a left component expressed as HRIR_L(U, r, theta, phi) and a right component expressed as HRIR_R(U, r, theta, phi).
 8. The electronic device of claim 7, wherein the produced audio sound comprises: a first output acoustic signal (YL) for a left ear of the first user; and a second output acoustic signal (YR) for a right ear of the first user, wherein YL is generated as: YL=X * HRIR L(U, r, theta, phi), wherein YR is generated as: YR=X * HRIR R(U, r, theta, phi), wherein * is a convolution operation and X corresponds to a sound signal that is different from the produced audio sound.
 9. The electronic device of claim 4, wherein the acquired attribute is a common attribute of users of the electronic device other than the first user, and the HRTF is an average head-related transfer function of the users of the electronic device other than the first user having the common attribute.
 10. The electronic device of claim 9, wherein the functionality is an unlock function, and the processing circuitry is further configured to unlock the electronic device for use based on the relationship between the virtual sound source position and the position information of the perceived sound source position.
 11. The electronic device of claim 1, further comprising: a head mounted display configured to be worn on a head of the first user; and a left speaker and a right speaker, configured to produce the audio sound in left and right ears of the first user respectively.
 12. The electronic device of claim 1, wherein the processing circuitry is further configured to: select the virtual sound source position as one of a plurality of spatial positions; compare the virtual sound source position with the position information of the perceived sound source position; and enable the functionality of the electronic device based on a determination that the perceived sound source position is a closer match to the virtual sound source position than to a spatial position other than the virtual sound source position of the plurality of spatial positions.
 13. The electronic device of claim 12, wherein the functionality is an unlock function, and the processing circuitry is further configured to unlock the electronic device for use based on the determination that the perceived sound source position is a closer match to the virtual sound source position than to the spatial position other than the virtual sound source position of the plurality of spatial positions.
 14. The electronic device of claim 1, further comprising a head mounted display configured to be worn on a head of the first user, and wherein the processing circuitry is further configured to: select the virtual sound source position as one of a plurality of different virtual sound source positions; and display indicia associated with the plurality of different virtual sound source positions.
 15. The electronic device of claim 1, wherein the processing circuitry is further configured to move the virtual sound source position based on acquisition of a plurality of user-inputs for the position information for a plurality of perceived sound source positions.
 16. The electronic device of claim 15, further comprising a line-of-sight input unit configured to track a line-of-sight of the first user on a displayed image to identify each of the plurality of the user-inputs for the position information for the plurality of perceived sound source positions.
 17. The electronic device of claim 1, wherein the processing circuitry is further configured to reproduce the audio sound of the virtual source corresponding to a user selectable attribute.
 18. The electronic device of claim 1, wherein the processing circuitry is further configured to: associate IDs for a plurality of different users; and identify the first user from the plurality of different users, wherein the functionality is an unlock function, and wherein the processing circuitry is further configured to unlock the electronic device for use based on: a selection of an ID for the first user; and determination of a match between the virtual sound source position and perceived sound source position for the first user.
 19. The electronic device of claim 1, wherein the acquired attribute is one of an age of the first user, an age group of the first user or a gender of the first user.
 20. An information processing method, comprising: in an electronic device: acquiring an attribute of a user of the electronic device; producing with a speaker an audio sound from a virtual sound source position based on a function that is determined based on the virtual sound source position and the acquired attribute; acquiring from an input by the user on an interface, a position information of a perceived sound source position; and controlling a functionality of the electronic device based on a relationship between the virtual sound source position and the position information of the perceived sound source position.
 21. A non-transitory computer-readable medium having stored thereon computer-executable instructions for causing a processing circuitry of an electronic device to execute operations, the operations comprising: acquiring an attribute of a user of the electronic device; producing with a speaker an audio sound from a virtual sound source position based on a function that is determined based on the virtual sound source position and the acquired attribute; acquiring from an input by the user on an interface, a position information of a perceived sound source position; and controlling a functionality of the electronic device based on a relationship between the virtual sound source position and the position information of the perceived sound source position. 